Air cushion



FIG. 1 is a front perspective view of an air cushion showing our new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a left side view thereof;

FIG. 5 is a right side view thereof;

FIG. 6 is a top plan view thereof;

FIG. 7 is a bottom plan view thereof;

FIG. 8 is a cross sectional view taken along line 8-8 of FIG. 3; and,

FIG. 9 is an enlarged view of portion 9 of FIG. 1. 

CLAIM The ornamental design for an air cushion, as shown and described. 